Examples of known methods for displaying stereoscopic images include glasses methods using glasses for stereoscopic viewing, and naked-eye methods for realizing stereoscopic viewing with the naked eye without glasses specially designed for stereoscopic viewing.
A typical one of the glasses methods is a shutter glasses method using shutter glasses that have a shutter for the left eye and a shutter for the right eye. By the shutter glasses method, a parallax image for the left eye and a parallax image for the right eye are alternately displayed on a two-dimensional display panel at a high speed in a frame sequential manner. As the shutter for the left eye and the shutter for the right eye are alternately closed in synchronization with displaying of each of the parallax images, only the parallax image for the left eye enters the left eye of the viewer, and only the parallax image for the right eye enters the right eye of the viewer. Accordingly, images can be stereoscopically viewed.
Meanwhile, typical naked-eye methods include a parallax barrier method and a lenticular method. In the case of the parallax barrier method or the lenticular method, parallax images for stereoscopic viewing (a parallax image for the right eye and a parallax image for the left eye in the case of two-viewpoint displaying) are spatially divided and are displayed on a two-dimensional display panel, and the parallax images are subjected to parallax separation in the horizontal direction by a parallax separating unit. In this manner, stereoscopic viewing is realized. By the parallax barrier method, a parallax barrier having slit-like openings as the parallax separating unit is used at this point. By the lenticular method, a lenticular lens having cylindrical split lenses arranged in parallel is used as the parallax separating unit.
Also, a device has been suggested as a display device using a naked-eye method in which the design proper viewing distance can be shortened by reducing the distance between the image forming surface of the liquid crystal panel and the parallax barrier (see Patent Document 1, for example).